Annual low-dose CT lung cancer screening for high-risk individuals doesn't have enough evidence for benefit over harms to be covered by Medicare, an advisory panel concluded.

The Centers for Medicare and Medicaid national coverage determination panel voted a mean 2.2 on a 5.0-point scale for confidence in that regard.

Key concerns were the high false-positive rate of CT screening, indication creep outside of the intended screening population, inability to assure quality scans with low radiation dose, and consistent interpretation and diagnostic workup in routine practice.

“If we don’t do it right now, it’s a genie that won’t be able to be stuffed back in the bottle,” Peter Bach, MD, MAPP, of Memorial Sloan-Kettering Cancer Center in New York City, who has been a prominent voice of caution in the national discussion, argued at the panel meeting.

The vote came in again at a low to intermediate level of 2.3 for confidence that harm could be minimized in the Medicare population.

The only thing the panel was confident about was that there are significant gaps in the evidence on how the screening would be used outside a clinical trial, with a mean vote of 4.4 on the 5.0-point scale.

The only reason that score wasn’t higher was that one of the voters flipped the scale and voted 2 when going for 4.

Generalizability

One of the main concerns cited was generalizability of the pivotal National Lung Screening Trial (NLST) upon which the U.S. Preventive Services Task Force (USPSTF) grade B recommendation was based and in turn prompted the national coverage determination.

Only a quarter of the trial population was 65 or older and none were enrolled past age 74.

Harms, particularly to those with chronic obstructive pulmonary disease (COPD) or other comorbidities, could be greater among older adults, Bach pointed out.

Lung cancer disproportionately affects older adults, both in terms of incidence and in deaths.

As of 2011, 14% of Medicare beneficiaries were current smokers and 44% were former smokers, Joseph Chin, MD, noted in introducing the topic on behalf of CMS at the meeting.

But the best estimate is that about 9% of Medicare beneficiaries would be eligible for screening under the criteria recommended by the USPSTF, Bruce Pyenson, an actuary with the consulting firm Milliman, told the panel.

Subgroup analysis of the 65 and older population within the NLST suggested a lower and nonsignificant 13% reduction in lung cancer mortality, although without a significant interaction by age on the impact of screening.

Panel member Harry Burke, MD, PhD, an internal medicine clinician at the Walter Reed National Military Medical Center in Bethesda, Md., called this the biggest reason he voted no confidence in the evidence for the Medicare population.

Another issue was that the majority of patients in the NLST were screened at large academic medical centers by experienced radiologists adhering to protocols for performance.

The same 20% lung cancer mortality reduction is unlikely to be replicated in the community setting, Doug Campos-Outcalt, MD, MPA, chair of family, community, and preventive medicine at the University of Arizona in Phoenix, told the panel.

He represented the American Academy of Family Physicians, which disagreed with the USPSTF on the B recommendation and called for designation as I for insufficient evidence.

“Community based screening can be performed responsibly,” said Vickie Beckler, RN, lung screening coordinator at the Wellstar community hospital system in Marietta, Ga. “Please do not impose barriers to access.”

One awkward consequence of no Medicare coverage would be that coverage will end right as people are entering the period of highest lung cancer incidence, commented James Jett, MD, a pulmonologist in the oncology division at National Jewish Health in Denver.

“Older Americans 65 and older will not have that opportunity,” he told MedPage Today. “It’s a tremendously missed opportunity by Medicare.”

Further data for the 65 and older population could come from a registry, uncontrolled observational findings, and ongoing randomized but smaller European trials.

There is not likely to be another trial like the NLST, noted guest panelist Michael Gould, MD, director of health services research and implementation science at Kaiser Permanente Southern California.

“We’re accustomed to making recommendations, thumbs up or thumbs down, everyone should get it,” he said, but the lesson has been learned from prostate specific antigen screening for prostate cancer. Lung cancer is even more “a poster child for the situation where every individual has to weigh benefits and harms.”

Quality Assurance

The 96% false positive rate among the 27% of positive scans found in the NLST drew plenty of attention.

The LUNGRADS structured reporting and management system criteria should help fix that, argued Ella Kazerooni, MD, director of cardiothoracic radiology at the University of Michigan in Ann Arbor and a representative for the American College of Radiology.

She said the criteria would bring the false-positive rate down to one in 10, although the panel seemed unconvinced without seeing data to back it up.

Another concern is “extreme variability” in the false-positive rates between radiologists in the NLST, noted Paul Pinsky, MD, of the National Cancer Institute Division of Cancer Prevention and one of the researchers in the NLST.

It ranged from 10% or lower for some but up around 50% or higher for others even among the experienced radiologists in the trial, he pointed out.

There was no standard algorithm to say what to recommend for follow-up in the trial, he added.

That level of variation in interpretation in a relatively controlled environment raises serious concerns as it rolls out in the community, said panelist Jo Carol Hiatt, MD, MBA, of Kaiser Permanente.

Inappropriate Use

However, with such nuanced screening recommendations there’s no reason to believe a coverage decision would be implemented that way in the community, argued panelist Allan M. Fendrick, MD, of the University of Michigan School of Public Health in Ann Arbor.

CMS is still spending a billion dollars on screening 80-year-olds for colon cancer despite lack of evidence for benefit in that group, he noted. “I do not want this to be PSA,” he said. “I have reservations.”

There is a tendency for criteria to slip to extending the criteria, which means the risk-benefit ratio of the NLST would no longer apply, agreed guest panelist Steven H. Woolf, MD, MPH, director of the Center on Society and Health at Virginia Commonwealth University in Richmond.

He cited the sentiment to move to screening a younger age group, to not stop screening at 80, and to expand the pack-year and thresholds expressed by representatives of various organizations at the meeting.

Also, it would be pragmatically difficult to hold to such thresholds given self-reported smoking history, he added. “The feasibility of expecting that to be done nationwide is quite challenging.”

“I have serious concerns that coverage will lead to an explosion of inappropriate activities driven by a mix of good intentions and unrestrained entrepreneurialism,” warned Bach, although he did support coverage with requirement for a registry and qualifications for screening sites.

He criticized the Lung Cancer Alliance list of “trusted” sites, noting that 68% of that group’s Centers of excellence he reviewed followed neither the USPSTF nor the professional societies’ recommended criteria for screening.

Gould expressed doubt that any principles issued for screening could be assured to be followed going forward and that it shouldn’t be up to a group like the Lung Cancer Alliance to set those standards.

“Have confidence in the professional societies,” that group’s president and CEO Laurie Fenton Ambrose responded.

Despite the uncertainty that gave screening such low scores, panel vice chair Art Sedrakyan, MD, PhD, called himself convinced that there is a large subgroup of patients that would gain substantial benefit from low-dose CT lung screening.

“We just need to find it,” said Sedrakyan, director of the Patient Centered Comparative Outcomes Research Program at Weill Cornell Medical School in New York City.

The proposed decision is due in mid-November, followed by a 30-day comment period and a final determination 90 days after that.

UPDATE: This article, originally published April 30, 2014, at 4:28 p.m., was updated with new material (April 30, 2014, at 8:25 p.m.).

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